1. Field of the Invention
The present invention relates to an energy storage apparatus, and more particularly, to an energy storage apparatus capable of preventing performance degradation by reducing resistance during movement of charges between layers in a multilayer capacitor with very high capacity such as a supercapacitor.
2. Description of the Related Art
Since a supercapacitor, which is a capacitor with very high capacitance, uses a charge phenomenon by movement of ions to the interface between an electrode and an electrolyte or a surface chemical reaction unlike a battery using a chemical reaction, it can perform rapid charge/discharge and has high charge/discharge efficiency and semipermanent life. Accordingly, a supercapacitor has been used as an energy storage apparatus for stable power supply to electronic products, electric vehicles, and industrial electronic devices.
This supercapacitor has a multilayer structure in which several electrode layers are stacked. That is, a cathode layer and an anode layer are alternately stacked, and a separation layer is present between the cathode layer and the anode layer to separate the cathode layer and the anode layer from each other. In the multilayer structure formed like this, in order to electrically connect electrodes, that is, an electrode of the cathode layer and an electrode of the anode layer to external devices, an electrical connection structure should be included.
In this case, due to characteristics of the multilayer structure, a charge present on each layer should face only the electrode in order to move to the electrode and a moving path of the charge is limited, thus causing performance degradation of the supercapacitor due to a resistance increase during the movement of the charge.